DE4107623C2 - Plasterboard with high fire resistance - Google Patents

Abstract

The gypsum board of high fire resistance with a gypsum core containing cut mineral fibres, preferably glass fibres, contains at least 2% by weight, preferably 5% by weight, of granulated aerated concrete. Preferably, the granulated aerated concrete has a grain size of up to 2 mm, particularly preferably up to 1 mm. The gypsum board can additionally contain up to 2% by weight of vermiculite. It can be laminated on the outside to a glass fibre mat.

Description

The subject of the present invention is a gypsum board with high fire resistance with a cut minera metallic fibers, preferably gypsum containing glass fibers core.

Generic gypsum boards are for example from the US-PS 33 76 147 known, with further essential Be constituents of the gypsum core unexpanded vermiculites and unge bloated Perlite are. These additives are said to be the dreaded Shrinkage and cracking when exposed to heat avoids the. There are additives of about 2% vermiculite and about 3% Perlite required in addition to about 0.45 to 0.5 wt .-% glass fibers, to come to reasonably usable results. Vermiculites and perlites are relatively expensive additives. The high-quality gypsum boards that can be produced with their help Fire resistance can qualitatively still wishes open.

There has been no lack of attempts to plasterboard with high To develop fire resistance. So are already from the DE-AS 10 95 187 fire-retardant building boards known, which with the addition of 8 to 12 wt .-% vermiculite and 8 bis 12% by weight of expanded perlite and 0.5 to 2% by weight of Pa pierschnitzel have been produced. The paper cut Zel may be used as an additional admixture to mineral fibers and / or asbestos fibers or even without the addition of fibers be added. The high levels of vermiculite and Perlite are in terms of cost and quantity of raw materials her not responsible.

From DE-OS 33 22 067 is a fire retardant component known, which consists of 40 to 55 wt .-% hemihydrate gypsum, 20 to 45% by weight Portland cement and 10 to 40% by weight endothermic constituents, where up to 10 wt .-% glass fibers can be added. The at Temperatures above 300 ° C endothermic components are, for example, alumina cement, dolomite, calcite, Fetton, unexpanded vermiculite or unperforated pearlite and aluminum hydroxide. These plates can in Gießver drive or on gypsum board plants or after the Hatschek process can be produced. These plates can thus contain only up to 55 wt .-% hemihydrate gypsum and require significant amounts of Portland cement and others partially valuable additives.

From US-PS 36 16 173 are fire-resistant gypsum Building boards with a relatively low volume weight and less Shrinkage at high temperatures known. They contain in addition to glass fibers about 1 to 3.5 wt .-% vermiculite, 0.5 to 20 wt .-% fine-grained inorganic substances from the Group of clays and optionally colloidal silicon dioxide or alumina. As clays are kaolinite, Mont morillonite, illite, chlorite, attapulgite, etc. Also These are relatively valuable additives. The plates thus obtained are in particular with respect the mechanical properties are desired.

From US-PS 46 47 486 gypsum boards with high fire known resistance, which is an essential part 2 to 40 wt .-% anhydrite II optionally together with Glass fibers, unexpanded vermiculite or wollastonite contain. Optimal results were only achieved under Use of deadburned calcium sulphate anhydrite II Fibers, a likewise relatively expensive additive.

Also valuable and relatively expensive additives, such as Boron, aluminum and silicon compounds are used for a highly reinforced fire described in EP-02 58 064 A2 stable plaster composition needed.

A method for producing lightweight panels a porous aggregate and gypsum, being the porous one Aggregate steam-hardened gas concrete fracture and / or waste material is and at least 50% in the finished Lightweight board is included in DE 25 24 147 B2 described. These are made by pouring into molds Plate does not contain the mechanical properties improving glass fibers.

A plate with a base layer consisting of plaster, lignocellulosic and / or cellulosic and / or an organic particles and at least one cover layer from plaster and filler is disclosed in DE 33 08 585 A1. This improved in surface quality plate be however, it has a low fire resistance.

The present invention has the object Plasterboard with high fire resistance with a ge cut glass fiber containing gypsum core continues to improve while using as little expensive additives to use. This task can be surprisingly to be solved by a gypsum board according to claim 1, preferably according to claims 2 to 6.

Concrete granules fall in the production of aerated concrete in relatively large quantities and can hardly be recovered so far recycled or reused. Continue to let Concrete granules are relatively simple and larger Quantities gain in the demolition of buildings made of aerated concrete. Until now, this material had to be used as voluminous building rubble could be deposited and could not use any more be fed. Gas concrete waste may be due to their mechanical behavior relatively easily and cost grinded to a particle size of less than 2 mm. Ge if necessary, the oversize is separated and again the Fed grinding process.

The inventive use of gas concrete granules thus represents an ecologically and economically meaningful Reuse of aerated waste. It allows In addition, the production of gypsum boards with high Fire resistance and excellent mechanical properties companies. These properties are not yet explained bar. Also the extensive literature and patent literature gives no indications of the invention usable of aerated concrete granules.

The plasterboard according to the invention can generally as further addition relatively small amounts of unblooded Vermiculite, wherein generally about 1 wt .-%, at most 2% by weight. The addition of Vermiculite compensates for the shrinkage on heating, However, form at higher levels in general my cracks. When using higher concentrations than 2 wt .-% vermiculite worsens the structure sammenhalt the plate at high temperature.

Essential part of the gypsum board according to the invention are cut glass fibers. In principle, too Mineral fibers or other inorganic fibers used However, glass fibers are due to the price and / or the processability preferred. These become more common Wise in amounts between 0.15 and 0.4 wt .-%, preferably in amounts between 0.2 and 0.3 wt .-%, added. Mostly it is about  Glass fibers, which are on lengths of about 12 mm are cut and in this shape and allow these quantities to disperse well in the gypsum core.

The gypsum core is usually made of settable Gypsum, preferably ordinary stucco, manufactured. the This stucco plaster can be made of natural plaster or even be calcined from technical gypsum.

The preparation of the gypsum board according to the invention can known production facilities for plasterboard as well other plasterboard to be produced. Usual accessories are, for example, starch, foaming agents and fine-looking lenes dihydrate as setting accelerator.

Another embodiment of the invention is a plaster plate, the one-sided or two-sided outside with fiberglass fleece is laminated. Also suitable is a glass fiber fleece, which Beschich on the side facing away from the plaster core tet is at least partially tied inorganic binder according to German patent application P 39 37 433. As inorganic binders are thereby fast-binding calcium sulfate hemihydrate, fastbin cement or quick-setting cement mixtures ver applies. High sulfate-resistant cement is particularly be vorzugt.

In the following examples are preferred Ausfüh tion forms as well as test and comparative tests together posed:

example 1

On a production plant for the production of gypsum cardboard plates were 12.5 mm thick gypsum plasterboard ago put, which except stucco and 0.22 wt .-% ge cut glass fibers (about 12 mm long), 8 wt .-% ge contained crushed gas concrete granules. The grain size of the Granules showed the following values in the sieve analysis:

<2.0 mm | 0% up to 2.0 mm 100.0% to 0.1 mm 91.7%, up to 0.5 mm 58.2%, to 0.125 mm 17.8% up to 0.09 mm 10.6%.

The bulk density of the granules was 0.68 kg / dm³. The chemical analysis of the granules revealed

31% CaO,
47% SiO₂,
4% Al₂O₃,
1% MgO,
2% Fe₂O₃,
1% alkalies,
11% loss on ignition.

The mixture was produced in small quantities during production Starch, foaming agent and finely ground dihydrate as Ab accelerator added.

The plates thus produced showed the mechanical Test same good properties as conventional Gypsum plaster boards (fire protection boards GKF according to DIN 18 180). Testing of fire resistance at an both sided, einlagig planked metal stud wall revealed against much better values. So that was delayed Falling of pieces of plate on the furnace side to the Factor 2. The local browning of cardboard on the Room side and the local temperature limit (Delta T <180 ° K; Wanderelement) improved by approx. 20%. Also the room completion (examination with cotton ball) improved significantly.

Example 2

On the same production line as in example 1 was a 12.5 mm thick, both sides with glass fiber fleece laminated plaster construction made. It contained 0.25% by weight cut glass fibers, 1 wt .-% vermiculite and 8 wt .-% gas concrete granules, ground to less than 1 mm was. For comparison, a plate was made, the instead of gas concrete granulate 4.8% by weight of expanded perlite ent held. The mechanical properties of the plates were again almost identical. The test of the fire resist Stands again resulted in significantly better values. It was found that when bilateral, single-layer planking metal stand wall with a mineral fiber insulation insert a fire resistance of 90 minutes is enough. The comparison plate reached only a fire resistance of 60 minutes.

Obviously, the addition of the invention reduces ground gas concrete granules both the formation of cracks, what was observed during the fire resistance tests, as well as the shrinkage. Orientational laboratory experiments have confirmed this. From the plates of Example 2 wur the rectangular specimen measuring 200 mm × 100 mm cut out. In a muffle furnace were the sample body at a temperature of 920 ° C for one hour puts. After that, they were taken out, to room tempera cooled and measured. While the comparison plate from Example 2 shrank by 6.8%, the shrinkage was the plates according to the invention only 4.1%. Another he Inventive plate, the 4 wt .-% gas concrete granulate ent stopped after the test showed a contraction of 5.2%.

The content of ground gas concrete granules should be min at least 2 wt .-% amount. Good results were found in Be rich achieved between 5 and 10 wt .-%. It appears possible higher amounts of aggregate up to 50% by weight However, gypsum is a cheaper component as ground gas concrete granules.

Claims (6)

1. gypsum board with high fire resistance with a ge cut mineral fibers, especially glass fibers blown perlites and conventional additives containing gypsum core, characterized in that the gypsum core instead of expanded perlites 2 to 20 wt .-% gas concrete granules with a grain size to 2 mm. 2. gypsum board according to claim 1, characterized that the gypsum core 5 to 10 wt .-% gas concrete granules contains. 3. gypsum board according to claim 1 or 2, characterized marked records that the gas concrete granules a grain size up to 1 mm. 4. gypsum board according to one of claims 1 to 3, characterized characterized in that the core additionally contains up to 2% by weight Contains vermiculite. 5. gypsum board according to one of claims 1 to 4, characterized characterized in that the Gispkern outside  laminated with glass fiber fleece. 6. gypsum board according to claim 5, characterized that the glass fiber fleece abge on the gypsum core turned side is coated with an at least partially bound inorganic binder.